Improvement in pistons



BECK.

PISTON.

Patented June 26-,'1877.

@NVENTOB:

WITNESSES:

moanns.

ROBERT M. BECK, OF WESTMINSTER,

MARYLAND, ASSIGNOR TO THE TAY- LOR MANUFACTURING COMPANY, OF SAME PLACE.

IMPROVEMENT 1N PISTONS.

Specification forming part of Letters Patent No. 192,409, dated June 26,1877; application filed May 21, 1877.

To all whom it may concern Be it known that 1, ROBERT M. BECK, ofWestminster, in the county of Carroll and State of Maryland, haveinvented anew and Improved Piston; and I do hereby declare that thefollowing is a full, clear, and exact description of the same, referencebeing had to the accompanying drawing, forming part of thisspecification, in which- Figure 1 is a side and Fig. 2 a sectional view;Fig. 3 a detail of the continuous softmetal packing-rin g.

My invention relates to an improved form of piston, designed primarilyto increase the durability and wearing qualities of the same; and itconsists in the particular construction and arrangement of parts, ashereinafter fully described and pointed out in the claim.

In the drawing, A represents the piston-rod, and B B the two disks, ofwhich E is pro vided with a central boss or hub, 11, and is made fastupon the pistonrod, while B is loose from the rod, and is provided witha central depression, b, corresponding to the hub 12, and also aconcentric perforation to receive the screw-threaded end a of thepiston-rod. These two disks are formed with beveled edges 0 c, and arebrought together by means of a screw-nut, d, arranged upon thescrewt-hreaded end of the piston-rod.

U is the packing-ring, which is made continuous and jointless, with aplain periphery and beveled inner edges corresponding to the bevel ofthe two disks. This ring is composed of any soft metal or composition ofmetal, but I prefer an alloy of tin and bismuth, as this is notinjurious to the cylinder, and makes a good wearing material.

To prevent the ring from being packed too tightly from the action of thesteam and thus rendered immovable in the cylinder, I locate a series ofsoft-metal washers, d, upon the boss 12 of the disk B, which washersdetermine the approach of one disk toward the other, and regulate theamount of the expansion of the ring to compensate for the wear, withoutder to permit the disks to approach the other so much, and by reason oftheir beveled edges give the proper amount of expansion to thepacking-ring, the hub b and recess 12 operating as guides in theadjustment of the loose disk, so as to hold the latter concentric.

I am aware of English Patent N 0. 2,076 of 1854, in which are shown thefeatures of the continuous packing-ring, and the guiding of the twoparts of the piston by a boss or hub, but the piston here shown cannotpermit the location of the Washers near the periphery, which, by reasonof the greater area presented, is the most desirable place to resiststeampacking, and it cannot employ a single nut to compress the twoparts of the piston in expandin g the ring.

I am also aware of theEnglish Patent No. 2,990 of 1873, in which isshown a single not for compressing the two parts of the piston, andwashers to determine their adjustment; but here it will be seen there isno boss and recess to efi'ect the guiding of the parts, and the washersare not arranged at their proper place near the periphery. 'By myarrangement it will be seen that I secure a threefold result; first, theexpansion of the packingring by a single nut; secondly, the guiding ofthe parts of the piston by the boss and recess; and, thirdly, thearrangement of the washers near the periphery of the piston and upon theboss of the stationary part of the same, whereby the efi'ect of thesteam upon the packingring is better obviated.

Having thus described my invention, what I claim as new is- Thecombination of the rigid disk B, having boss I), and the loose disk B,having depression b, with the interposed adjustingwashers (1, arrangedupon the boss 1) near the periphery of the piston, and the continuous orjointless expansible metallic packing-ring C, substantially asdescribed, and for the purpose set forth.

.ROBT. M. BECK.

Witnessesi -G. A. TAYLOR,

J. E. TAYLOR, J. J. BAUMGARTNER, Jr.

